Devices for supplying materials



ay 30, 1967 F. FRASER @V32-2,37

DEVICES FOR SUPPLYING MATERIALS Filed Aug. 19, 1.965 2 Sheetswfhee't l May 30, 1967 F. FRASER 3,322,3'?

DEVICES FOR SUPPLYING MATERIALS Filed Aug. 19, 1965 2 Sheets-Sheet 2 United States Patent Oiice 3,322,307 Patented May 3i), 1967 This invention relates to supply devices for supplying required quantities of a plastic or other liowable niateral. The invention is in particular intended for supplying quantities of a dentists amalgam for iilling cavities in patients teeth, but can be used for other purposes.

It has been common practice for many years for dentists to use tools comprising a tube containing a plunger. The plunger can leave a small space in the end of the tube which the dentist tills with a small quantity of amalgam. The dentist then carries the tool to the patient and presses the plunger to expel the amalgam from the tube into the cavity in the patients tooth. For a larve cavity or when order to take up a amalgam and transfer these to the patient. This is time absorbing and inconvenient to the patient and to the dentist, It is not practicable to fill a long tube with amalgam and try to press this out by a plunger because the amalgam becomes compacted and jams in the tube.

According to the present invention a collapsible tubular device is provided to contain the plastic material, said device having walls which slide into one another so as to eject the material. The tubular device may be a container having an opening at one end through which the material is ejected.

The material may be ejected into the path of a plunger which can be .l

The spring collapses axially with the helices sliding one within the other.

ln an alternative construction the device comprises a series of separate flat section rings of progressively diminishing diameters, so that each (except the largest) within the next largest ring,

companying drawings wherein:

FIGURE l is a sectional View of a device made in accordance with the invention;

FIGURE 2 is an enlarged View of part of FIGURE l;

FIGURES 3 to 6 are views of separate parts of FIG- URE l; and

FIGURE 7 is an enlarged sectional view of the nozzle.

The device comprises a tube or barrel 1i) closed at one end by a cap 11 that carries a spigot l2 that can be pushed into the end of `the barrel. Near the cap the barrel has a tube 13 detachably fixed to it with its axis at an angle of about 45 to the axis of the barrel and extending above the cap. A nozzle i4 is screwed on to the tube 13. The nozzle 14 has a bore of smaller diameter than the tube 13. Between the outer end of tube 13 and the inner end of the bore of the nozzle is an elastic tapering rubber guide 9 the large end of which is about the same size as the bore of the tube 13 and the small on the side opposite the nozzle and in alignment therewith is a second tube or barrel 16 which has a straight part E7, followed by a curved part 18 leading to a straight part 19 that is parallel to the rst barrel 10.

10 has an internal barrel 10 a head 29 is Within the hollow plunger 27 is a 39 to the plunger 27 and having one end which projects out of the rubber piston 41 at its inner end the rod into the plunger, a space $2, in the plunger between the piston d1 and the nozzle 26 can be progressively reduced in size. The outer end of the plunger 27 also carries a knurled knob 44.

Within the straight part 17 of the second barrel 16 is an outer tubular plunger 45 which slidably contains an inner plunger 46. The tightly wound helical spring 43 to plunger 49 located in the straight part 19 of the second barrel. The inner plunger 46 is connected by a helical spring Si@ to a second inner plunger 51 that is slidable in plunger 49. A spring S3 surrounds the plunger 49 and engages between an internal annular shoulder 54 in the barrel i6 and a flange 5S on one end of the plunger 49. A spring 56 surrounds part rod 38 screwed at .a knurled knob 40 at plunger and carries a and the pullsoiT cap removed, the instrua mix of amalgam through a small funnel inserted in place of the cap, by holding the instrument vertically and shaking or vibrating it. The amalgam falls down and more or less ills the interior of the volute spring. The cap is then replaced.

Assuming suiicient amalgam has been loaded to ll the spring, pressure is applied to the plunger 27 with the thumb, to move the plunger and compress the spring 22. As the spring is compressed amalgam will be from within it into a space 61 just above the spring. As soon as a unit measure of amalgam has been expelled, the stop pin 33 will engage in a groove 28 on the plunger 27 with a click. If this quantity is suicient for the operator he transfers his thumb to the operating knob 60 and presses this, but if not he can compress the spring 22 to a second or third groove 28. Pressure on the handle knob G actuates the two concentric plungers in barrel 116. They move forward together carrying the pellet of amalgam (or a part of it) towards the exit nozzle. When this point is reached further progress of the outer plunger is halted by contact with the tapered rubber guide 9. The inner plunger 46 continues on through the exit nozzle 14 which it closely fits, carrying the pellet forward in advance of itself. At the end of its travel the inner plunger projects slightly beyond the nozzle and can be used as a plugger to consolidate the amalgam into the tooth cavity. The operating handle is then released and returns to its extended position, the two concentric plungers being retracted. The procedure can now be repeated by alternately pressing the two operating heads until the spring 22 is completely closed and its contents used.

Lifting the knurled head 36 releases the spring which can then return to its open position ready for a fresh charge of amalgam. If desired plunger 27 can be completely withdrawn from the barrel together with the spring for quick cleaning.

Spring 56 is of heavier gauge than spring 49. This ensures that the inner concentric plunger will not move out of the mouth of the outer plunger until the latter is brought to rest by the tapered rubber washer.

VThe inner plunger 51 is connected to the piston S3 and therefore moves directly forwards and backwards with the movement of knob 60; the outer plunger however is moved through the force of the spring 56.

When contact of the outer plunger 45 with the rubber washer occurs, there is a momentary expansion of the rubber followed by contraction to normal shape. This assists in contracting the diameter of the pellet to assist its expulsion through the exit nozzle. A small residue of amalgam may remain. However, as the volute spring 22 is progressively emptied, the pellet gradually reduces in diameter until, at the end, it is the same diameter as the exit, so that little or no residue will finally remain. The nozzle nevertheless is quickly removable for ease of cleaning.

The space 42 serves as a reservoir to contain mercury. By removing rod 3S the reservoir can be filled, After rod 38 is replaced with its rubber face making contact with the column of mercury within, any further motion of the rod will then expel mercury through the small orifice in the nozzle 26 into the spring space. This allows for possible delay in utilising the whole charge of amalgam within the instrument, during which time the amalgam may begin to set. The addition of a small extra quantity of mercuryV restores its plasticity. As only a very small quantity of mercury is required at a time the contents -of the reservoir sufce for many mixes.

Additionally, by giving knob 44 a half-turn during the earlier stages of compression, the volute spring is rotated so as to present the residue of amalgam more directly to plunger 45.

In a modification the instrument is designed in which,

by suitable linkage the compression of the volute spring 22 and ejection of the amalgam at the exit nozzle are both effected by one control knob.

The cylinder may be shaped to receive a small funnel into which the amalgam may be placed. By placing the device against a vibrator such as is commonly used for mixing the amalgam the amalgam is caused to move down the funnel into the collapsible device.

claim:

1. A device for supplying quantities of a iiowable material comprising a substantially rigid tubular member, a collapsible tapering volute spring to contain the material, and means for injecting material into one end of the spring and for compressing the spring, said spring having walls which slide into one another so as to eject the material only from the other end of the spring.

2. A device as claimed in claim 1 wherein the rigid tubular member has an opening at one end through which the material is ejected and a tapered elastic guide and an outlet nozzle of smaller diameter than said opening, said guide being located between said opening and said nozzle.

3. A device as claimed in claim il wherein the said means for injecting the material and compressing the spring comprises a plunger, and wherein stop means are provided to locate the plunger in various positions of increasing axial disposition.

4. A device as claimed in claim 1 wherein said injecting means comprises a rod screwed into a bore in the plunger, said plunger having a nozzle leading to the interior of said tubular device.

7. A device as claimed in claim 2 wherein the axis of said opening is at an angle to the axis of said tubular member, and wherein an ejecting device is attached to said member in alignment with said opening.

6. A device as claimed in claim S wherein said ejecting device comprises inner and outer plungers, one within the other, and means for moving the plungers so that the inner plunger moves further than the outer plunger during ejection.

'7. A device as claimed in claim 5 wherein said ejecting device comprises a barrel having a straight part in line with said opening, a second straight part parallel with said tubular member, and a curved part between them, first and second plungers in the straight parts, re spectively, the plungers being connected together by ex ible means, and a piston in the second straight part.

B. A device as claimed in claim 7 having an inner plunger in each of said plungers and slidable therein and connected together by fiexible means, the inner plunger in the second straight part being fixed to the piston, a spring urging the second plunger to its rest position.

References Cited UNiTED STATES PATENTS 1,930,037 10/1933 Brubaker 222-95 X 3,216,616 11/1965 Blankenship 222-386 X 3,221,409 12/1965 Thiel et al. 222-391 X j FORETGN PATENTS 309,333 4/1929 Great Britain.

ROBERT B. REEVES, Primary Examiner. S. H. TOLLBERG, Assistant Examiner. 

1. A DEVICE FOR SUPPLYING QUANTITIES OF A FLOWABLE MATERIAL COMPRISING A SUBSTANTIALLY RIGID TUBULAR MEMBER, A COLLAPSIBLE TAPERING VOLUTE SPRING TO CONTAIN THE MATERIAL, AND MEANS FOR INJECTING MATERIAL INTO ONE END OF THE SPRING AND FOR COMPRESSING THE SPRING, SAID SPRING HAVING WALLS WHICH SLIDE INTO ONE ANOTHER SO AS TO EJECT THE MATERIAL ONLY FROM THE OTHER END OF THE SPRING. 